Does the AstraZeneca-Pfizer deal make scientific sense?

FORTUNE — Is the proposed merger of Pfizer PFE and AstraZeneca AZN a tax dodge, a cost-cutting cornucopia, or the ultimate in complementary research? It may well end up being all of the above.

But since most of the attention thus far has been on the financial implications of the deal, it’s worth taking a closer look at Pfizer CEO Ian Read’s claim, made on Tuesday in a hearing before Britain’s Business Select Committee, that the two companies have “complementary portfolios of information in cardiovascular, metabolic and oncology.”

Amsterdam-based The ANT Works, an R&D analytics startup, has put together an interactive visual look at both companies’ research–based on patent filings–as a means by which to assess Read’s claim. The ANT Works analyzed over 57.000 patent documents, which include patent applications and granted patents in the US, EU and Japan between 1994-2012. Provided exclusively to Fortune, the interactive map shows where there are clear overlaps–which it is fair to say will lend themselves to job cuts–and where each company has unique strengths.

The main conclusion of the data is that Pfizer is by far the dominant player when it comes to research, with roughly 80% of the registered patents connected to research areas compared with AstraZeneca’s 20%. That also implies that the therapeutic areas with the greatest overlap, such as cardiovascular, neurosciences, and cardiology will be most likely to be cut at AstraZeneca, says Thomas Gurney, CSO at The ANT Works. “If you look at this from the science perspective, he says, “if there is a merger, most likely the AstraZeneca scientists will lose.” That’s a big part of the reason why AstraZeneca is resisting so far (in addition to its assertion that the offer itself is too low). Indeed, AstraZeneca head Pascal Soriot showed up at the hearings with two of his head scientists in tow to make a point.

But the graphic also shows areas where AstraZeneca offers access to a potential brand new pipeline for Pfizer, giving some credence to Read’s claims as well. There’s enough here for ammunition on either side—but it’s nice to have data rather than simply politics in the mix.

Overview of all technology areas covered by the 57,000 patents of Pfizer and AstraZeneca. Pfizer is in blue and AstraZeneca is in yellow. Click on the image for a link to the interactive.

Technology areas unique to Pfizer. Click on the image for a link to the interactive.

Technology areas unique to AstraZeneca. Click on the image for a link to the interactive.